/*
 * Copyright 2017 ~ 2025 the original author or authors. James Wong <jameswong1376@gmail.com>>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.wl4g.infra.common.remoting.uri;

import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.util.Arrays;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

import javax.annotation.Nullable;
import com.wl4g.infra.common.collection.multimap.LinkedMultiValueMap;
import com.wl4g.infra.common.collection.multimap.MultiValueMap;
import com.wl4g.infra.common.lang.StringUtils2;

/**
 * Utility class for URI encoding and decoding based on RFC 3986. Offers
 * encoding methods for the various URI components.
 *
 * <p>
 * All {@code encode*(String, String)} methods in this class operate in a
 * similar way:
 * <ul>
 * <li>Valid characters for the specific URI component as defined in RFC 3986
 * stay the same.</li>
 * <li>All other characters are converted into one or more bytes in the given
 * encoding scheme. Each of the resulting bytes is written as a hexadecimal
 * string in the "<code>%<i>xy</i></code>" format.</li>
 * </ul>
 *
 */
public abstract class UriUtils {

    /**
     * Encode the given URI scheme with the given encoding.
     * 
     * @param scheme
     *            the scheme to be encoded
     * @param encoding
     *            the character encoding to encode to
     * @return the encoded scheme
     */
    public static String encodeScheme(String scheme, String encoding) {
        return encode(scheme, encoding, HierarchicalUriComponents.Type.SCHEME);
    }

    /**
     * Encode the given URI scheme with the given encoding.
     * 
     * @param scheme
     *            the scheme to be encoded
     * @param charset
     *            the character encoding to encode to
     * @return the encoded scheme
     * @since 5.0
     */
    public static String encodeScheme(String scheme, Charset charset) {
        return encode(scheme, charset, HierarchicalUriComponents.Type.SCHEME);
    }

    /**
     * Encode the given URI authority with the given encoding.
     * 
     * @param authority
     *            the authority to be encoded
     * @param encoding
     *            the character encoding to encode to
     * @return the encoded authority
     */
    public static String encodeAuthority(String authority, String encoding) {
        return encode(authority, encoding, HierarchicalUriComponents.Type.AUTHORITY);
    }

    /**
     * Encode the given URI authority with the given encoding.
     * 
     * @param authority
     *            the authority to be encoded
     * @param charset
     *            the character encoding to encode to
     * @return the encoded authority
     * @since 5.0
     */
    public static String encodeAuthority(String authority, Charset charset) {
        return encode(authority, charset, HierarchicalUriComponents.Type.AUTHORITY);
    }

    /**
     * Encode the given URI user info with the given encoding.
     * 
     * @param userInfo
     *            the user info to be encoded
     * @param encoding
     *            the character encoding to encode to
     * @return the encoded user info
     */
    public static String encodeUserInfo(String userInfo, String encoding) {
        return encode(userInfo, encoding, HierarchicalUriComponents.Type.USER_INFO);
    }

    /**
     * Encode the given URI user info with the given encoding.
     * 
     * @param userInfo
     *            the user info to be encoded
     * @param charset
     *            the character encoding to encode to
     * @return the encoded user info
     * @since 5.0
     */
    public static String encodeUserInfo(String userInfo, Charset charset) {
        return encode(userInfo, charset, HierarchicalUriComponents.Type.USER_INFO);
    }

    /**
     * Encode the given URI host with the given encoding.
     * 
     * @param host
     *            the host to be encoded
     * @param encoding
     *            the character encoding to encode to
     * @return the encoded host
     */
    public static String encodeHost(String host, String encoding) {
        return encode(host, encoding, HierarchicalUriComponents.Type.HOST_IPV4);
    }

    /**
     * Encode the given URI host with the given encoding.
     * 
     * @param host
     *            the host to be encoded
     * @param charset
     *            the character encoding to encode to
     * @return the encoded host
     * @since 5.0
     */
    public static String encodeHost(String host, Charset charset) {
        return encode(host, charset, HierarchicalUriComponents.Type.HOST_IPV4);
    }

    /**
     * Encode the given URI port with the given encoding.
     * 
     * @param port
     *            the port to be encoded
     * @param encoding
     *            the character encoding to encode to
     * @return the encoded port
     */
    public static String encodePort(String port, String encoding) {
        return encode(port, encoding, HierarchicalUriComponents.Type.PORT);
    }

    /**
     * Encode the given URI port with the given encoding.
     * 
     * @param port
     *            the port to be encoded
     * @param charset
     *            the character encoding to encode to
     * @return the encoded port
     * @since 5.0
     */
    public static String encodePort(String port, Charset charset) {
        return encode(port, charset, HierarchicalUriComponents.Type.PORT);
    }

    /**
     * Encode the given URI path with the given encoding.
     * 
     * @param path
     *            the path to be encoded
     * @param encoding
     *            the character encoding to encode to
     * @return the encoded path
     */
    public static String encodePath(String path, String encoding) {
        return encode(path, encoding, HierarchicalUriComponents.Type.PATH);
    }

    /**
     * Encode the given URI path with the given encoding.
     * 
     * @param path
     *            the path to be encoded
     * @param charset
     *            the character encoding to encode to
     * @return the encoded path
     * @since 5.0
     */
    public static String encodePath(String path, Charset charset) {
        return encode(path, charset, HierarchicalUriComponents.Type.PATH);
    }

    /**
     * Encode the given URI path segment with the given encoding.
     * 
     * @param segment
     *            the segment to be encoded
     * @param encoding
     *            the character encoding to encode to
     * @return the encoded segment
     */
    public static String encodePathSegment(String segment, String encoding) {
        return encode(segment, encoding, HierarchicalUriComponents.Type.PATH_SEGMENT);
    }

    /**
     * Encode the given URI path segment with the given encoding.
     * 
     * @param segment
     *            the segment to be encoded
     * @param charset
     *            the character encoding to encode to
     * @return the encoded segment
     * @since 5.0
     */
    public static String encodePathSegment(String segment, Charset charset) {
        return encode(segment, charset, HierarchicalUriComponents.Type.PATH_SEGMENT);
    }

    /**
     * Encode the given URI query with the given encoding.
     * 
     * @param query
     *            the query to be encoded
     * @param encoding
     *            the character encoding to encode to
     * @return the encoded query
     */
    public static String encodeQuery(String query, String encoding) {
        return encode(query, encoding, HierarchicalUriComponents.Type.QUERY);
    }

    /**
     * Encode the given URI query with the given encoding.
     * 
     * @param query
     *            the query to be encoded
     * @param charset
     *            the character encoding to encode to
     * @return the encoded query
     * @since 5.0
     */
    public static String encodeQuery(String query, Charset charset) {
        return encode(query, charset, HierarchicalUriComponents.Type.QUERY);
    }

    /**
     * Encode the given URI query parameter with the given encoding.
     * 
     * @param queryParam
     *            the query parameter to be encoded
     * @param encoding
     *            the character encoding to encode to
     * @return the encoded query parameter
     */
    public static String encodeQueryParam(String queryParam, String encoding) {
        return encode(queryParam, encoding, HierarchicalUriComponents.Type.QUERY_PARAM);
    }

    /**
     * Encode the given URI query parameter with the given encoding.
     * 
     * @param queryParam
     *            the query parameter to be encoded
     * @param charset
     *            the character encoding to encode to
     * @return the encoded query parameter
     * @since 5.0
     */
    public static String encodeQueryParam(String queryParam, Charset charset) {
        return encode(queryParam, charset, HierarchicalUriComponents.Type.QUERY_PARAM);
    }

    /**
     * Encode the query parameters from the given {@code MultiValueMap} with
     * UTF-8.
     * <p>
     * This can be used with
     * {@link UriComponentsBuilder#queryParams(MultiValueMap)} when building a
     * URI from an already encoded template.
     * 
     * <pre class="code">
     * MultiValueMap&lt;String, String&gt; params = new LinkedMultiValueMap<>(2);
     * // add to params...
     *
     * ServletUriComponentsBuilder.fromCurrentRequest().queryParams(UriUtils.encodeQueryParams(params)).build(true).toUriString();
     * </pre>
     * 
     * @param params
     *            the parameters to encode
     * @return a new {@code MultiValueMap} with the encoded names and values
     * @since 5.2.3
     */
    public static MultiValueMap<String, String> encodeQueryParams(MultiValueMap<String, String> params) {
        Charset charset = StandardCharsets.UTF_8;
        MultiValueMap<String, String> result = new LinkedMultiValueMap<>(params.size());
        for (Map.Entry<String, List<String>> entry : params.entrySet()) {
            for (String value : entry.getValue()) {
                result.add(encodeQueryParam(entry.getKey(), charset), encodeQueryParam(value, charset));
            }
        }
        return result;
    }

    /**
     * Encode the given URI fragment with the given encoding.
     * 
     * @param fragment
     *            the fragment to be encoded
     * @param encoding
     *            the character encoding to encode to
     * @return the encoded fragment
     */
    public static String encodeFragment(String fragment, String encoding) {
        return encode(fragment, encoding, HierarchicalUriComponents.Type.FRAGMENT);
    }

    /**
     * Encode the given URI fragment with the given encoding.
     * 
     * @param fragment
     *            the fragment to be encoded
     * @param charset
     *            the character encoding to encode to
     * @return the encoded fragment
     * @since 5.0
     */
    public static String encodeFragment(String fragment, Charset charset) {
        return encode(fragment, charset, HierarchicalUriComponents.Type.FRAGMENT);
    }

    /**
     * Variant of {@link #encode(String, Charset)} with a String charset.
     * 
     * @param source
     *            the String to be encoded
     * @param encoding
     *            the character encoding to encode to
     * @return the encoded String
     */
    public static String encode(String source, String encoding) {
        return encode(source, encoding, HierarchicalUriComponents.Type.URI);
    }

    /**
     * Encode all characters that are either illegal, or have any reserved
     * meaning, anywhere within a URI, as defined in
     * <a href="https://tools.ietf.org/html/rfc3986">RFC 3986</a>. This is
     * useful to ensure that the given String will be preserved as-is and will
     * not have any o impact on the structure or meaning of the URI.
     * 
     * @param source
     *            the String to be encoded
     * @param charset
     *            the character encoding to encode to
     * @return the encoded String
     * @since 5.0
     */
    public static String encode(String source, Charset charset) {
        return encode(source, charset, HierarchicalUriComponents.Type.URI);
    }

    /**
     * Convenience method to apply {@link #encode(String, Charset)} to all given
     * URI variable values.
     * 
     * @param uriVariables
     *            the URI variable values to be encoded
     * @return the encoded String
     * @since 5.0
     */
    public static Map<String, String> encodeUriVariables(Map<String, ?> uriVariables) {
        Map<String, String> result = new LinkedHashMap<>(uriVariables.size());
        uriVariables.forEach((key, value) -> {
            String stringValue = (value != null ? value.toString() : "");
            result.put(key, encode(stringValue, StandardCharsets.UTF_8));
        });
        return result;
    }

    /**
     * Convenience method to apply {@link #encode(String, Charset)} to all given
     * URI variable values.
     * 
     * @param uriVariables
     *            the URI variable values to be encoded
     * @return the encoded String
     * @since 5.0
     */
    public static Object[] encodeUriVariables(Object... uriVariables) {
        return Arrays.stream(uriVariables).map(value -> {
            String stringValue = (value != null ? value.toString() : "");
            return encode(stringValue, StandardCharsets.UTF_8);
        }).toArray();
    }

    private static String encode(String scheme, String encoding, HierarchicalUriComponents.Type type) {
        return HierarchicalUriComponents.encodeUriComponent(scheme, encoding, type);
    }

    private static String encode(String scheme, Charset charset, HierarchicalUriComponents.Type type) {
        return HierarchicalUriComponents.encodeUriComponent(scheme, charset, type);
    }

    /**
     * Decode the given encoded URI component.
     * <p>
     * See {@link StringUtils#uriDecode(String, Charset)} for the decoding
     * rules.
     * 
     * @param source
     *            the encoded String
     * @param encoding
     *            the character encoding to use
     * @return the decoded value
     * @throws IllegalArgumentException
     *             when the given source contains invalid encoded sequences
     * @see StringUtils#uriDecode(String, Charset)
     * @see java.net.URLDecoder#decode(String, String)
     */
    public static String decode(String source, String encoding) {
        return StringUtils2.uriDecode(source, Charset.forName(encoding));
    }

    /**
     * Decode the given encoded URI component.
     * <p>
     * See {@link StringUtils#uriDecode(String, Charset)} for the decoding
     * rules.
     * 
     * @param source
     *            the encoded String
     * @param charset
     *            the character encoding to use
     * @return the decoded value
     * @throws IllegalArgumentException
     *             when the given source contains invalid encoded sequences
     * @since 5.0
     * @see StringUtils#uriDecode(String, Charset)
     * @see java.net.URLDecoder#decode(String, String)
     */
    public static String decode(String source, Charset charset) {
        return StringUtils2.uriDecode(source, charset);
    }

    /**
     * Extract the file extension from the given URI path.
     * 
     * @param path
     *            the URI path (e.g. "/products/index.html")
     * @return the extracted file extension (e.g. "html")
     * @since 4.3.2
     */
    @Nullable
    public static String extractFileExtension(String path) {
        int end = path.indexOf('?');
        int fragmentIndex = path.indexOf('#');
        if (fragmentIndex != -1 && (end == -1 || fragmentIndex < end)) {
            end = fragmentIndex;
        }
        if (end == -1) {
            end = path.length();
        }
        int begin = path.lastIndexOf('/', end) + 1;
        int paramIndex = path.indexOf(';', begin);
        end = (paramIndex != -1 && paramIndex < end ? paramIndex : end);
        int extIndex = path.lastIndexOf('.', end);
        if (extIndex != -1 && extIndex > begin) {
            return path.substring(extIndex + 1, end);
        }
        return null;
    }

}